Severe ARDS caused by Strongyloides stercoralis hyperinfection in a patient with Sjögren's syndrome: a case report.

BACKGROUND: Strongyloides stercoralis (S. stercoralis) is a neglected tropical disease that can be fatal in immunocompromised hosts. Diagnosis is challenging due to nonspecific clinical manifestations and low sensitivity of conventional stool examination. Patients with autoimmune diseases receiving long-term glucocorticoid therapy are at high risk of hyperinfection syndrome, which can rapidly progress to acute respiratory distress syndrome (ARDS). CASE PRESENTATION: A 65-year-old man with an 8-year history of Sjögren's syndrome and chronic interstitial lung disease, who had been on long-term oral methylprednisolone, tripterygium glycosides, and hydroxychloroquine, presented with abdominal pain and vomiting. He rapidly developed severe ARDS requiring invasive mechanical ventilation. Laboratory tests showed persistent eosinopenia (0.01 × 109/L) and lymphopenia. Bronchoalveolar lavage fluid was subjected to metagenomic capture sequencing (MetaCAP), which revealed S. stercoralis [16,030 reads per million (RPM)] and cytomegalovirus (14,397RPM). Sputum smear microscopy showed motile S. stercoralis larvae, confirming the diagnosis. The patient was treated with albendazole (0.4 g via nasogastric tube twice daily) combined with ivermectin (12 mg via nasogastric tube once daily) for strongyloidiasis, together with ganciclovir for cytomegalovirus. Because of severe ARDS and possible autoimmune flare, methylprednisolone (80 mg intravenously every 12 h followed by tapering) was cautiously administered under effective anti-infective coverage. Two days after treatment, the oxygenation index improved from 77 mmHg to 214 mmHg. One week later, repeat MetaCAP showed a marked reduction of S. stercoralis reads to 69RPM and cytomegalovirus 9 RPM. The patient was successfully extubated and discharged after consolidation therapy. At nine-month follow-up he remained well. CONCLUSION: This case demonstrates that S. stercoralis hyperinfection can occur without eosinophilia in immunocompromised patients with autoimmune diseases and can rapidly progress to ARDS. MetaCAP of bronchoalveolar lavage fluid enables rapid and sensitive diagnosis. Short-term glucocorticoid therapy to control ARDS and autoimmune disease activity is feasible and safe provided that effective anti-infective treatment is in place.